This invention relates to the use of D-tagatose as a low-calorie carbohydrate sweetener and bulking agent in the preparation of sweetened edible formulations.
J. D. Dziezak in Food Technology, Vol. 112 (January, 1986) states that: "The ideal sweetener, as described by the Calorie Control Council (1985) should have the same or greater sweetness as sucrose in addition to being colorless, odorless, readily soluble, stable, functional and economically feasible. The ideal sweetener should contribute reduced or no calories to the diet, be normally metabolized or resistant to digestion and be non-toxic and non-promoting of dental caries. To date, the ideal sweetener is not commercially available".
Commercially available intense sweeteners typically have problems with thermal and/or aqueous instability, reproduction of the true sweetness of sucrose, the requirement of a bulking agent to simulate the functional properties of sugars, and imputed health problems.
U.S. Pat. No. 4,262,032 to Levin proposes the use of L-hexose sugars as the solution to this problem. The taste quality and relative sweetness of L-hexoses are identical to the respective D-hexoses. Bulking agents are not required. All functional properties of L-hexoses are identical to those of the respective D-hexoses. Physical properties in general are identical, with the exception of the direction of the rotation of polarized light. Chemical properties of the D- and L-enantiomers are identical in non-chiral environments, while in the presence of many enzymes chemical properties are quite different. It is this difference in enzymically mediated chemical reactivities coupled with the identical sweetness of the D- and L-hexoses that makes the L-hexose concept viable.
D-Tagatose is a naturally-occurring keto-hexose. Although this material is not commonly found in nature, it has been reported to occur in the gum of the Sterculia setigera date and in the lichens Rocella linearis and Rocella fucoformis. One research group has identified D-tagatose in strongly heated (120.degree. C., 8-10 hours) cow's milk. H. R. Moskowitz in American Journal of Psychology, Vol. 84, No. 3, pages 387-405 (1971), reports a sweetness level for D-tagatose of 0.5 times that for a 1% by weight sucrose solution.